✦GEOGRAPHIA ORTUS LUNAE
OBSERVED
TOPOCENTRIC ASTROMETRY · SUB-LUNAR ZENITH & HORIZON GEOMETRY

Moonrise Geography

Global topocentric altitude, azimuth, instantaneous sub-lunar zenith coordinate, and local horizon visibility across worldwide meteorological stations.

USNO / HMNAO AlgorithmsDiscipline: 02 // ASTRONOMIC

GEOGRAPHIA ORTUS LUNAE · GUIDED TOPOCENTRIC SWEEP

The Moon moves. The horizon translates.

Follow one lunar coordinate as it becomes a different sky at every station on Earth.

01 · SUB-LUNAR ZENITH

At one point on Earth, the Moon is overhead.

The sub-lunar point is the moving place where the Moon crosses the local meridian at 90° altitude. Every other observer measures distance from that moving center.

Sub-lunar latitude-6.34°
Visible stations50%
UTC TIME SWEEP01 Jan 1970 · 00:00
−12 HNOW+12 H
Sub-lunar field00:00 UTC
ZENITHGreenwichNew YorkTokyoCairoSydneyHonoluluReykjavikCape TownSantiagoMumbai
Zenith longitude+88.70°
Stations above horizon5 / 10

Local horizon sample

Greenwich

-4.5°

Below Horizon (Invisible) · azimuth 95°

The UTC sweep recomputes the sub-lunar field and every station from the same topocentric solver.

Earth / Lunar horizon

The Moon from here.

One Moon. A different horizon at every longitude.

Computed snapshot · UTC
North up · Equirectangular180° W — 180° E
Sub-lunar pointSelected stationAbove horizon
Directly beneath the Moon Geocentric, spherical-Earth reference—
Map source & calculation notes
Natural Earth land, 1:110 million ↗

Natural Earth contributors; Tom Patterson and Nathaniel Vaughn Kelso. Public Domain. Natural Earth 4.1.0 geography redistributed by world-atlas. Equirectangular projection with antimeridian clipping; generalized coastlines, not navigation-grade.

Coordinates: Astronomy Engine, apparent equator of date. Station altitudes use observer-specific parallax and standard refraction at sea level. Snapshot refreshes each minute while this page is visible.

Natural Earth usage terms ↗